Steering lock

ABSTRACT

A steering lock for locking a rotary steering member against rotation. A lockbolt is movable along a first axis between steering member-locking and -unlocking positions. A shuttle moves between a non-blocking position, in which the shuttle does not obstruct movement of the lockbolt from the steering member-locking position, and a blocking position, in which the shuttle obstructs movement of the lockbolt out of the steering member-locking position. An actuator drives the lockbolt to the steering member-locking position by moving the shuttle to the blocking position. An output gear is drivable by the actuator. A rotary drive member has a first portion formed with gear teeth meshed with the output gear, and a second portion formed with a driving structure engaged with a follower structure of the shuttle, whereby the shuttle is configured to translate axially toward and away from the first axis when the rotary drive member rotates in place.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/698,197 filed Sep. 7, 2012 and to U.S. Provisional PatentApplication No. 61/810,444 filed Apr. 10, 2013, the entire contents ofboth of which are incorporated by reference herein.

BACKGROUND

The present invention relates to locking mechanisms for locking (i.e.,preventing unauthorized rotation of) a rotary steering member such as asteering wheel, handlebar, etc. of a vehicle.

Conventional steering column locks use an actuator mechanism to drive alocking pin into and out of locking engagement with a steering shaft.Efficient transfer of motion can be accomplished by directly driving thelocking pin back and forth. However, certain circumstances may arise inwhich the locking pin becomes substantially wedged against one of therecesses in the steering shaft. In order to account for this occurrence,the electric motor that drives the locking pin and the correspondingelectric drive circuit for the motor must have current/power ratingssubstantially higher than what is required for normal operation (whenthe locking pin is not wedged). Also, complex gear reduction devices maybe implemented in order to multiply the torque output of the motor. Ineither case, the locking device as a whole becomes more costly andcomplicated, and may generate excessive noise.

SUMMARY

In one construction, the invention provides a steering lock forselectively inhibiting rotation of a rotary steering member having arib. The steering lock includes a lockbolt movable along a first axisbetween a steering member-locking position, in which a distal tip of thelockbolt is positioned in interference with the rib, and a steeringmember-unlocking position, in which the distal tip of the lockbolt ispositioned out of interference with the rib. A shuttle is movablebetween a non-blocking position, in which the shuttle does not obstructmovement of the lockbolt from the steering member-locking position tothe steering member-unlocking position, and a blocking position, inwhich the shuttle obstructs movement of the lockbolt out of the steeringmember-locking position. An actuator is coupled to the shuttle andoperable to drive the lockbolt to the steering member-locking positionby moving the shuttle from the non-blocking position to the blockingposition. A lost motion connection is provided between the actuator andthe lockbolt. Motive force from the actuator is transmitted through thelost motion connection to drive the lockbolt to the steeringmember-locking position when the rib is not aligned with the first axis,and motive force from the actuator is taken up by the lost motionconnection when the rib is aligned with the first axis.

In another construction, the invention provides a steering lock forselectively inhibiting rotation of a rotary steering member having arib. The steering lock includes a lockbolt movable along a first axisbetween a steering member-locking position, in which a distal tip of thelockbolt is positioned in interference with the rib, and a steeringmember-unlocking position, in which the distal tip of the lockbolt ispositioned out of interference with the rib. A shuttle is movablebetween a non-blocking position, in which the shuttle does not obstructmovement of the lockbolt from the steering member-locking position tothe steering member-unlocking position, and a blocking position, inwhich the shuttle obstructs movement of the lockbolt out of the steeringmember-locking position. An actuator is coupled to the shuttle andoperable to drive the lockbolt to the steering member-locking positionby moving the shuttle from the non-blocking position to the blockingposition. A lost motion connection is provided between the actuator andthe lockbolt. The lost motion connection is configured to store energysupplied from the actuator when the shuttle from the non-blockingposition to the blocking position while the rib is aligned with thefirst axis. The lockbolt is movable to the steering member-lockingposition by the stored energy of the lost motion connection when the ribis moved away from the first axis.

In yet another construction, the invention provides a steering lock forselectively inhibiting rotation of a rotary steering member having arib. The steering lock includes a lockbolt movable along a first axisbetween a steering member-locking position, in which a distal tip of thelockbolt is positioned in interference with the rib, and a steeringmember-unlocking position, in which the distal tip of the lockbolt ispositioned out of interference with the rib. A shuttle is movablebetween a non-blocking position, in which the shuttle does not obstructmovement of the lockbolt from the steering member-locking position tothe steering member-unlocking position, and a blocking position, inwhich the shuttle obstructs movement of the lockbolt out of the steeringmember-locking position. An actuator is coupled to the shuttle andoperable to drive the lockbolt to the steering member-locking positionby moving the shuttle from the non-blocking position to the blockingposition. The lockbolt is unbiased along the first axis.

In yet another construction, the invention provides a steering lock forselectively inhibiting rotation of a rotary steering member having arib. The steering lock includes a lockbolt movable along a first axisbetween a steering member-locking position, in which a distal tip of thelockbolt is positioned in interference with the rib, and a steeringmember-unlocking position, in which the distal tip of the lockbolt ispositioned out of interference with the rib. A shuttle moves between anon-blocking position, in which the shuttle does not obstruct movementof the lockbolt from the steering member-locking position, and ablocking position, in which the shuttle obstructs movement of thelockbolt out of the steering member-locking position. An actuator isoperatively coupled to the shuttle and operable to drive the lockbolt tothe steering member-locking position by moving the shuttle from thenon-blocking position to the blocking position. An output gear isdrivable by the actuator. A rotary drive member has a first portionformed with gear teeth meshed with the output gear, and a second portionformed with a driving structure engaged with a follower structure of theshuttle, whereby the shuttle is configured to translate axially towardand away from the first axis when the rotary drive member is rotated inplace. In some constructions, the driving structure of the rotary drivemember includes a spiral cam (e.g., a spiral cam groove). In otherconstructions, the driving structure of the rotary drive member includesa threaded drive portion and the shuttle includes a threaded followerstructure.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a steering lock in a locked state.

FIG. 2 is a perspective view of the steering lock of FIG. 1 in anunlocked state.

FIG. 3 is a perspective view of an actuation device of the steering lockof FIG. 1.

FIG. 4 is a second perspective view of the actuation device of FIG. 3.

FIG. 5 is a cross-sectional view of the steering lock, taken along line5-5 of FIG. 1.

FIG. 6 is a cross-sectional view of the steering lock, taken along line6-6 of FIG. 2.

FIG. 7 is a cross-sectional view of the steering lock of FIG. 1 in astate in which a lockbolt is obstructed from reaching the locked statewhen actuated.

FIG. 8 is a perspective view of a steering lock according to anotherconstruction in which the output shaft is offset from the actuator axis.

FIG. 9 is a perspective view of a steering lock according to anotherconstruction in which a rotary shuttle is provided.

FIG. 10 is a perspective view of the steering lock of FIG. 9 in a lockedstate.

FIG. 11 is a perspective view of the steering lock of FIG. 9 in anunlocked state.

FIG. 12 is a perspective view of the steering lock of FIG. 9 in a statein which a lockbolt is obstructed from reaching the locked state whenactuated.

FIG. 13 is a perspective view of a steering lock according to anotherconstruction having a passive lockbolt.

FIG. 14 is a partially exploded assembly view of the steering lock ofFIG. 13 in which the housing is removed from the actuation device.

FIG. 15 is front view of the steering lock of FIG. 13 in a locked state.

FIG. 16 is a front view of the steering lock of FIG. 13 in an unlockedstate.

FIG. 17 is a front view of the steering lock of FIG. 13 in a state inwhich the lockbolt is obstructed from reaching the locked state whenactuated.

FIG. 18 is a cross-sectional view of a steering lock according toanother construction.

FIG. 19 is a detail cross-sectional view of a lockbolt and shuttle ofthe steering lock of FIG. 18.

FIG. 20 is a side view of an actuation mechanism of the steering lock ofFIG. 18, shown in the unlocked state.

FIG. 21 is a side view of the actuation mechanism of the steering lockof FIG. 18, shown in the locked state.

FIG. 22 is a perspective view of an output shaft and crank of theactuation mechanism.

FIG. 23 is a perspective view of a steering lock according to anotherconstruction.

FIG. 24 is a perspective view of an actuation mechanism of the steeringlock of FIG. 23.

FIG. 25 is a perspective view of a steering lock according to anotherconstruction.

FIG. 26 is an alternate perspective view of the steering lock of FIG.25.

FIG. 27 is a perspective view of the steering lock of FIGS. 25-26 with acover portion of the housing removed to illustrate the actuationmechanism therein.

FIG. 28 is a perspective view identical to FIG. 27, but having a gearboxsub-housing removed to illustrate a gear train. The lockbolt is in thelocked state.

FIG. 29 is a perspective view identical to FIG. 28, but with thelockbolt in the unlocked state.

FIG. 30 is a perspective view of the actuation mechanism of the steeringlock of FIGS. 25-29. The lockbolt is in the locked state, as in FIG. 28.

FIG. 31 is an alternate perspective view of the actuation mechanism ofthe steering lock of FIGS. 25-29. The lockbolt is in the locked state,as in FIGS. 28 and 30.

FIG. 32 is a cross-sectional view of the steering lock of FIGS. 25-29 ina state in which the lockbolt is in the unlocked state.

FIG. 33 is a cross-sectional view of the steering lock of FIGS. 25-29 ina state in which the lockbolt is in the locked state.

FIG. 34 is a perspective view of a steering lock and actuation mechanismsimilar to that of FIGS. 25-33, but having an alternate housing.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

FIGS. 1 and 2 illustrate a steering lock 100 operable to selectivelylock an adjacent steering member 104 against rotation about its axis A.The steering lock 100 includes a housing 108 that is mounted at apredetermined location proximate the steering member 104. A cover 112 isremovably coupled to the housing 108 to enclose an actuation device 116of the steering lock 100. The actuation device 116, illustrated in FIGS.3 and 4 and discussed in further detail below, includes a lockbolt 120that is movable between a steering member-locking position or simply“locked” position (FIG. 1) and a steering member-unlocking position orsimply “unlocked” position (FIG. 2). In the illustrated construction,the lockbolt 120 is movable between the locked and unlocked positionsalong an axis B that is substantially perpendicular to the axis A of thesteering member 104.

As shown in at least FIGS. 1 and 2, the ring-shaped steering member 104includes a plurality of notches or grooves 124 that are elongatedparallel to the axis A. Each adjacent pair of grooves 124 are separatedby a rib 128. When the steering lock 100 is locked, the lockbolt 120 ispositioned within one of the grooves 124, and interference between thelockbolt 120 and the two adjacent ribs 128 prevent substantial rotationof the steering member 104 about the axis A. The size, shape, and numberof the grooves 124 and the ribs 128 can be varied from the illustratedconstruction according to the needs of a particular application.Although limited rotation of the steering member 104 may be possible insome circumstances when locked by the steering lock 100, the steeringmechanism (e.g., steering wheel, handlebars, etc.) to which the steeringmember 104 is coupled is rendered unusable for normal operation of thevehicle on which the steering lock 100 is provided.

As shown in FIGS. 3 and 4, the actuation device 116 includes an actuator132 and a shuttle 136 in addition to the lockbolt 120. The actuator 132of the illustrated construction is an electric motor, although othertypes of actuators may be used. As discussed in further detail below, insome constructions the actuator 132 is an electric motor rated for lessthan 1.0 A of current at max load. In some constructions, the actuator132 is an electric motor rated for about 500 mA of current at max load.As shown in FIGS. 3 and 4, the actuator 132 includes an output shaft140. In the illustrated construction, the output shaft 140 is a leadscrew rotatable about an axis C defined by the actuator 132. The leadscrew may have a pitch of about 10 teeth per inch.

Although the output shaft 140 is provided as a direct rotary drivemember extending directly from the actuator 132, the actuator 132 may becoupled to the output shaft 140 by a power transmission device such as agear train having one or more gears that alter the torque and speed ofthe output shaft 140. In such constructions, the output shaft 140 mayhave an axis that is different from the axis of the actuator 132, andmay be linearly offset or angled relative thereto. Such an arrangementmay not only provide a desired gear ratio but also a desired orientationof components (e.g., for more efficient packaging, etc.). For example,FIG. 8 illustrates a steering lock 200 including an output shaft 240that is offset from the actuator 232. Except as described herein, thesteering lock 200 is otherwise substantially identical to the steeringlock 100 of FIGS. 1-7. As such, similar reference characters (withleading digits increased by 100) are used for similar parts whereappropriate. Reference is made to the above description of the steeringlock 100 for features and aspects of the steering lock 200 of FIG. 8 notspecifically described below.

In the steering lock 200 of FIG. 8, the output shaft 240 is offset fromthe axis C2 of the actuator 232. In the illustrated construction, theoutput shaft 240 is parallel to the axis C2 of the actuator 232 and iscoupled to the actuator 232 by a power transmission device (e.g., geartrain). Although other offset arrangements are optional, the actuator232 includes a shaft 239 provided with a drive gear 241. The outputshaft 240 is provided with a driven gear 243 that is rotated by thedrive gear 241 of the actuator 232. The driven gear 243 and the outputshaft 240 form a rotary drive member which is drivable by the actuator232 and is operable to drive the shuttle 236. The available torque atthe output shaft 240 is increased and its angular velocity is decreasedby driving it through the two gears 241, 243 instead of being drivendirectly by the shaft 239 of the actuator 232. Thus, the output shaft240 (which is configured as a lead screw in the illustratedconstruction) may be provided with fewer threads per inch than theoutput shaft 140 of the steering lock 100 of FIGS. 1-7. For example, theoutput shaft 240 of FIG. 8 may be provided with only about 4 teeth perinch. The housing 208 is provided with a pair of internal cradles 249for rotatably supporting the output shaft 240 on both sides of thedriven gear 243.

Returning now to the construction illustrated in FIGS. 1-7, the shuttle136 is engaged with the output shaft 140 to be moved between twopositions by the actuator 132. The first position of the shuttle 136 isa blocking position (FIG. 3) in which the shuttle 136 obstructs movementof the lockbolt 120 from the locked position (FIG. 1) to the unlockedposition (FIG. 2). The second position of the shuttle 136 is anon-blocking position in which the shuttle 136 does not obstructmovement of the lockbolt 120 from the locked position (FIG. 1) to theunlocked position (FIG. 2). As described in further detail below, theshuttle 136 is configured to move in a plane P that is substantiallyperpendicular to the lockbolt axis B.

In some constructions, as shown in FIGS. 3-7, the shuttle 136 includes acam roller 144 and the lockbolt 120 includes a cam follower surface 148.In the illustrated construction, the cam follower surface 148 isopposite a tip or engagement end 152 of the lockbolt 120 which isengageable with the steering member 104. The cam follower surface 148includes a first portion 148A that is inclined relative to both thelockbolt axis B and the plane P in which the shuttle moves and a secondportion 148B that is substantially perpendicular to the lockbolt axis Band parallel to the shuttle's plane of movement P. Movement of the camroller 144 along the cam follower surface 148 occurs with rollingcontact which limits the amount of friction that the actuator 132 mustovercome to move the shuttle 136.

The shuttle 136 further includes a guide body 156, which supports andguides the cam roller 144. In the illustrated construction, the camroller 144 is mounted on a shaft 160 that extends through a slot 164formed in the guide body 156. The slot 164 is elongated in a directionsubstantially perpendicular to the lockbolt axis B. A spring 168 of theshuttle 136 biases the shaft 160 and the cam roller 144 to an end of theslot 164 that is furthest away from the output shaft 140 of the actuator132. In the illustrated construction, the spring 168 is a torsion springthat can function as a lost motion device as described in further detailbelow.

The guide body 156 of the shuttle 136 includes a threaded aperture 172that is engaged with the output shaft 140 of the actuator 132 andcoaxial with its axis C. In the illustrated construction, the outputshaft 140, which is a lead screw, rotates about the axis C and drivesmotion of the shuttle along the axis C (within the shuttle's plane ofmovement P). In other constructions, the output shaft 140 of theactuator 132 may be configured to move in and out of the actuator 132along the axis C such that the shuttle 136 may be fixed relative to theoutput shaft 140 and moved directly with the output shaft 140. In yetother constructions, the actuator 132 may be configured to rotate theshuttle 136 (within the plane P) between the blocking position and thenon-blocking position. Furthermore, a separate nut (not shown) may beprovided rather than providing the threaded aperture 172 directly in theguide body 156. This not only allows different materials to be used forthe guide body 156 and the nut as desired, but also allows theestablishment of a dynamic relationship between the nut and the guidebody 156. For example, the nut can be made slidable within the guidebody 156 so that, when the output shaft 140 rotates, the nut travelsrelative to the guide body 156 and achieves a running speed beforecontacting the guide body 156. This reduces the starting load on theactuator 132 and provides an impact-type actuation of the shuttle 136,and specifically the guide body 156.

As shown in FIGS. 3 and 4, the shuttle 136 includes auxiliary rollers176 mounted on the shaft 160 of the cam roller 144. The auxiliaryrollers 176, the shaft 160, and the cam roller 144 constitute a rollerunit of the shuttle 136 that is movable relative to the guide body 156.The auxiliary rollers 176 are guided by internal guide surfaces 178 ofthe housing 108 and the cover 112. The guide surfaces 178 are flat sothat the contact between the auxiliary rollers 176 and the guidesurfaces 178 keep the movement of the shuttle 136 within the desiredplane P. The auxiliary rollers 176 provide a guiding function withrolling contact which limits the amount of friction that the actuator132 must overcome to move the shuttle 136.

As shown in FIGS. 5-7, the housing 108 includes an internal recess 180in which the lockbolt 120 is positioned. The internal recess 180 isprovided with a plurality of guide surfaces 184 that guide movement ofthe lockbolt 120 along the axis B. A spring 188 is positioned betweenrespective abutment surfaces 192, 196 of the lockbolt 120 and theinternal recess 180. The spring 188 biases the lockbolt 120 in adirection along the axis B that tends to retract the lockbolt 120 intothe housing 108 and away from the steering member 104. In other words,the spring 188 biases the lockbolt 120 toward the unlocked position.

In operation, the steering lock 100 is kept in the unlocked state (FIGS.2 and 6) during normal operation of the vehicle. In this manner, thesteering member 104 can rotate freely about its axis A withoutobstruction from the lockbolt 120. Upon being commanded by the operatoror automatically by a predetermined function of the vehicle's securitysystem, the steering lock 100 can be moved to the locked state (FIGS. 1and 5).

In order to move the steering lock 100 to the locked state, the actuator132 is powered. Powering the actuator 132 may include supplyingelectrical current to an electric motor via an electrical circuit, butmay alternately include supplying energy to the output shaft 140 bymechanical or fluid means. When the output shaft 140 is constructed as alead screw, rotation of the output shaft 140 drives the guide body 156to move parallel to the axis C of the actuator 132. The spring 168between the guide body 156 and the cam roller 144 is strong enough totransfer the motion from the guide body 156 to the cam roller 144 sothat the cam roller 144 rolls from the inclined first portion 148A ofthe cam follower surface 148 to the second portion 148B, therebyovercoming the bias of the lockbolt spring 188 and moving the lockbolt120 to the locked position (FIG. 5).

The above description of how the actuation device 116 moves the lockbolt120 to the locked position assumes that the lockbolt 120 is aligned withone of the notches 124 of the steering member 104 and not one of theintermediate ribs 128. However, there is a significant chance that, atthe time that the actuator 132 is powered to move the steering lock 100from the unlocked state to the locked state, the lockbolt 120 will bealigned with one of the ribs 128. This occurrence is illustrated in FIG.7. In the event that the lockbolt 120 is aligned with one of the ribs128 when actuated, the actuator 132 still actuates and moves the guidebody 156 of the shuttle 136 just as it would if the lockbolt 120 werealigned with one of the notches 124. However, the movement of thelockbolt 120 is stopped prematurely when the tip 152 contacts the top ofthe rib 128. As the actuator 132 continues to move the guide body 156,the spring 168 acts as a lost motion device, storing energy while thecam roller 144 remains in contact with the inclined cam follower surfaceportion 148A. The slot 164 in the guide body 156 allows the guide body156 to move relative to the shaft 160 and the cam roller 144. The lostmotion device prevents an overloading of the actuator 132 when thelockbolt 120 contacts the top of a rib 128 and allows the lockbolt 120to later move to the locked position without further powering theactuator 132. As soon as the steering member 104 is moved slightly toremove the obstructing rib 128 from the path of the lockbolt 120, theenergy stored in the spring 168 is released, driving the cam roller 144to the second portion of the cam follower surface 148B andsimultaneously moving the lockbolt 120 into the locked position.

In some instances, one of the ribs 128 of the steering member 104 maybecome wedged against the lockbolt 120 when the lockbolt 120 is in thelocked position. For example, this may occur when one or more of thesteerable wheels coupled to the steering member 104 are wedged against astationary object, such as a curb. When a wedged condition exists and itis desired to move the steering lock 100 from the locked state to theunlocked state (thereby withdrawing the lockbolt 120 from the steeringmember 104), the actuator 132 operates normally and one or more passivefeatures assist in releasing the lockbolt 120 from the wedged condition.The steering lock 100 does not rely on the power supplied by theactuator 132 to extract or “un-wedge” the lockbolt 120. In fact, theactuator 132 and the shuttle 136 provide “push-only” actuation of thelockbolt 120, and in some constructions, are not coupled in a mannerthat enables urging of the lockbolt 120 toward the unlocked position bythe power of the actuator 132. Because the actuator 132 is not designedto extract the lockbolt 120 from a wedged condition, the power ratingfor the actuator 132 can be kept low. This lends to lower cost of theactuator 132 and associated running circuitry as well as generallysmaller size and easier packaging.

One passive feature that aids in releasing the lockbolt 120 from awedged condition is the tapered tip 152 of the lockbolt 120. Whenlocked, two tapered surfaces 152A of the tip 152 interfere with andpotentially contact the steering member ribs 128 are tapered by an angleα. from the adjacent flat sides of the lockbolt 120. Because theadjacent flat sides of the lockbolt 120 are substantially parallel withthe lockbolt axis B, the same angle α is made between the taperedsurfaces 152A and the lockbolt axis B. From the wedged condition,rotation of the steering member 104 causes the side of one of the ribs128 to contact one of the tapered surfaces 152A of the tip 152. Thus,torque from the steering member 104 generates a camming reaction alongaxis B that urges the release of the lockbolt 120 from the wedgedcondition with the steering member 104. In some constructions, the angleα is between about 10 degrees and about 20 degrees. When the angle α ismade too high, torque from the steering member 104 is transmitted to alarge degree along the axis B of the lockbolt 120. These large forcesmust be borne by the actuation device 116 to keep the lockbolt 120 inthe locked position. Thus, the structural demands on the shuttle 136,the output shaft 140, etc. are higher. On the other hand, when the angleα is made too small, a very large torque from the steering member 104 isrequired to produce a camming force (along axis B) sufficient to releasethe lockbolt 120 from the wedged condition. In certain constructions,such as the illustrated construction, an angle α between about 12degrees and about 16 degrees may provide an advantageous balance ofthese design considerations.

Another passive feature that aids in releasing the lockbolt 120 from awedged condition is the spring 188, which is compressed from its at-reststate when the lockbolt 120 is in the locked position. Therefore, thespring 188 stores energy that urges the lockbolt 120 to the unlockedposition whenever the lockbolt 120 is in the locked condition, includingwhen in a wedged condition.

As mentioned above, the operation of the actuator 132 is not affectedwhatsoever by the existence of a wedged condition. The actuator 132operates to draw the shuttle 136 and thus the cam roller 144 out of theblocking position of FIG. 5 and toward the non-blocking position of FIG.6. However, movement of the shuttle 136 does not directly cause movementof the lockbolt 120 to the unlocked position. Once the shuttle 136 andthe cam roller 144 are moved out of the way, the tapered tip 152 and thespring 188 work together to drive the lockbolt 120 from the wedgedcondition without active pulling or powered extraction via the actuator132 or any other powered device acting on the lockbolt 120.

FIGS. 9-12 illustrate a steering lock 300 according to yet anotherconstruction. The steering lock 300 of FIGS. 9-12 is similar in manyaspects to the steering lock 100 of FIGS. 1-7. Reference characters,with leading digits incremented by 100, are re-used where appropriatefor consistency. Reference is made to the above description of thesteering lock 100 for features and aspects of the steering lock 300 ofFIGS. 9-12 not specifically described below.

FIG. 9 illustrates the steering lock 300 without the cover of thehousing 308, and FIGS. 10-12 illustrate the steering lock 300 withoutthe housing 308 at all so that the actuation device 316 can be seenclearly. As with the steering lock 100, the steering lock 300 of FIGS.9-12 includes a lockbolt 320 that is movable between a steeringmember-locking position or simply “locked” position (FIG. 10) and asteering member-unlocking position or simply “unlocked” position (FIG.11). In the illustrated construction, the lockbolt 320 is movablebetween the locked and unlocked positions along an axis B3 that issubstantially perpendicular to the axis A3 of the steering member 304.

The actuator 332 of the steering lock 300 includes an output shaft 340provided with a drive gear 341. The output shaft 340 and the drive gear341 define an axis C3. The shuttle 336 is driven back and forth betweenblocking and non-blocking positions by the drive gear 341. In theillustrated construction, a plurality of intermediate gears 343 arepositioned between the drive gear 341 and a set of gear teeth 345 on theguide body 356 of the shuttle 336. The intermediate gears 343 provide areduction in angular velocity and an increase in torque from the outputshaft 340. The intermediate gears 343 serve as rotary drive members thatare drivable by the actuator 332 and operable to drive the shuttle 336,which in the illustrated construction is also rotatable or pivotable.

The guide body 356 pivots within the housing and moves in a plane P3that is perpendicular with the axis C3 of the output shaft 340 andparallel to the axis B3 of the lockbolt 320. In some constructions, theguide body 356 and actuator 332 have alternate orientations. Forexample, the guide body 356 and actuator 332 may be configured to beturned 90 degrees so that the axis C3 of the output shaft 340 isparallel to the axis B3 of the lockbolt 320 and the guide body 356 movesin a plane that is perpendicular to the axis B3 of the lockbolt 320. Thehousing 308 includes at least one internal guide surface (not shown)similar to those of the housing 108 for guiding movement of the guidebody 356, however the guide surface is arc-shaped to guide the pivotingmovement of the guide body 356.

In addition to the guide body 356, the shuttle 336 includes a cam roller344 and auxiliary rollers 376. The cam roller 344 is mounted on a shaft360 that is received in an arc-shaped slot 364 in the guide body 356.The cam roller 344 contacts an arc-shaped cam follower surface 348 toselectively actuate the lockbolt 320 from the unlocked position to thelocked position. Similar to the actuation device 116 described above,the actuator 332 and the shuttle 336 are only operable to actuate thelockbolt 320 to the locked position and block the lockbolt 320 fromreturning to the unlocked position, and are not configured to activelyretract the lockbolt 320 from the locked position.

Unlike the shuttle 136 of FIGS. 1-7 in which the shaft 160 simply slidesback and forth in the slot 164 to allow movement of the cam roller 144relative to the guide body 156, the shaft 360 on which the cam roller344 of the steering lock of FIGS. 9-12 is supported by a pivot arm 375that is coupled to the guide body 356 with a pivot shaft 377.

Similar to the shuttle 136 described above, the shuttle 336 includes aspring 368 that biases the shaft 360 and the cam roller 344 to one endof the slot 364. In the illustrated construction, the spring 368 is atorsion spring that can function as a lost motion device when, at thetime that the actuator 332 is powered to move the lockbolt 320 from theunlocked position to the locked position, the lockbolt 320 is alignedwith one of the ribs 328 on the steering member 304. When this occurs,the spring 368 stores energy as the guide body 356 moves to the blockingposition and the cam roller 344 remains in the non-blocking position.The slot 364 in the guide body 356 allows the guide body 356 to moverelative to the shaft 360 and the cam roller 344. The lost motion deviceprevents an overloading of the actuator 332 when the lockbolt 320contacts a rib 328. As soon as the steering member 304 is moved slightlyto remove the obstructing rib 328 from the path of the lockbolt 320, theenergy stored in the spring 368 is released so that the cam roller 344drives the lockbolt 320 into the locked position and blocks it fromretraction to the unlocked position.

FIGS. 13-17 illustrate a steering lock 400 according to yet anotherconstruction. The steering lock 400 of FIGS. 13-17 is similar in someaspects to the steering locks 100, 200, 300 of FIGS. 1-12. Referencecharacters, with leading digits incremented by 100, are re-used whereappropriate for consistency. Reference is made to the above descriptionof the steering locks 100, 200, 300 for features and aspects of thesteering lock 400 of FIGS. 13-17 not specifically described below.

As shown in FIGS. 13 and 14, the housing 408 includes first and secondhousing portions 408A, 408B, which in the illustrated construction, areconfigured as housing halves. The first and second housing portions408A, 408B are of complementary shape and are coupled together byfasteners 409, which may include threaded fasteners such as the twoillustrated screws that are located at overlapping areas of the twohousing portions 408A, 408B. Similar to the steering locks describedabove, the housing 408 is configured to be mounted at a predeterminedlocation proximate a steering member 404, and an actuation device 416 ofthe steering lock 400 is configured to selectively move a lockbolt 420out of the housing 408 from a steering member-unlocking position orsimply “unlocked” position (FIG. 16) to a steering member-lockingposition or simply “locked” position (FIG. 15). In the illustratedconstruction, the lockbolt 420 is movable between the locked andunlocked positions along an axis B4 that is substantially perpendicularto the axis A4 of the steering member 404.

In one construction, the steering member 404 is substantially identicalto the ring-shaped steering members 104, 204, 304 described above andincludes a plurality of notches or grooves 424 that are elongatedparallel to the axis A4, with each adjacent pair of grooves 424 beingseparated by a rib 428. When the steering lock 400 is locked, thelockbolt 420 is positioned within one of the grooves 424, andinterference between the lockbolt 420 and the two adjacent ribs 428prevents substantial rotation of the steering member 404 about the axisA4. The size, shape, and number of the grooves 424 and the ribs 428 canbe varied from the illustrated construction according to the needs of aparticular application. It should also be appreciated that the actuationdevice 416 of the steering lock 400, and any of the others describedabove, may engage virtually any type of steering member to selectivelyinhibit the use thereof. For example, the steering member in someconstructions may not be tubular or ring-shaped withoutwardly-projecting ribs, and may instead have a projection-free outersurface that provides one or more lockbolt-receiving grooves in the formof one or more apertures. One or more ribs for interfering with thelockbolt 420 in such a construction may simply be provided by thematerial adjacent the aperture(s).

As shown in FIG. 14, each of the housing portions 408A, 408B isconfigured to receive and support the actuation device 416. A combinedactuator mounting plate and printed circuit board (PCB) 411 is jointlyreceived by both housing portions 408A, 408B, with the edges 411A of themounting plate/PCB 411 being received by channels 413 provided on theinterior of the housing portions 408A, 408B. Two actuator mounts 415 aresecured to the mounting plate/PCB 411 and support opposing ends of theactuator 432. An additional support 417, which may be a bearing supportreceived by the second housing portion 408B, is provided on the end ofthe output shaft 440. In some constructions, the PCB 411 may not beconfigured as a mounting plate for the actuator 432. In suchconstructions, the actuator 432 may be electrically coupled with the PCB411 while being positioned by and/or mounted to at least one of thehousing portions 408A, 408B.

Turning now to the mechanics of the actuation device 416, certainaspects are generally similar to aspects already described with respectto at least one of the steering locks 100, 200, 300 described above. Forexample, the actuation device 416 utilizes a shuttle 436 to deploy thelockbolt 420 to the locked position. The shuttle is movable between ablocking position that obstructs movement of the lockbolt 420 to thesteering member-unlocking position and a non-blocking position that doesnot obstruct movement of the lockbolt 420 to the steeringmember-unlocking position. Furthermore, a lost motion device is providedto store the actuation energy as described above when the lockbolt 420is actuated to move from the unlocked position to the locked position,but is blocked from immediately achieving the locked position. However,unlike the steering locks 100, 200, 300 described above, the lockbolt420 of the steering lock 400 is completely passive, as no bias member isprovided to urge the lockbolt 420 along the lockbolt axis B4 to oneposition or the other. The specific construction and operation of theactuation device 416 are explained in detail below.

The actuator 432, which may be an electric motor rated for less than 1.0amp at maximum load and in some constructions about 500 mA at maximumload, is coupled to the output shaft 440 to rotate the output shaft 440about the axis C4. In the illustrated construction, the output shaft 440is constructed as a worm gear that is in meshed engagement with a gearportion 443A of a rotary drive member or crank 443. The gear portion443A forms a driven portion of the crank 443, and a driving portion 443Bis rotationally coupled and axially offset from the gear portion 443A.The crank 443 is configured to rotate about an axis D4 when the outputshaft 440 is rotated by the actuator 432. As shown in FIG. 14, a pair ofcradles 445 are formed in the first housing portion 408A for supportingthe crank 443.

The shuttle 436 is coupled to the crank 443 and configured to apply anactuating force to the lockbolt 420. The shuttle 436 includes a guidebody or link 456 coupled to the crank 443 at a pivot 457, and a rollerunit coupled to the link 456 through a lost motion device. In theillustrated construction, the roller unit includes a pair of rollerbearings 476 mounted on a common axle 460, and the lost motion deviceincludes a biasing member such as a coil spring 468 positioned in anopening or slot 464 of the link 456. As seen in the drawings, a firstend of the coil spring 468 may abut a first end 464A of the slot 464 andbe retained on a post 459 of the link 456, and the opposing end of thecoil spring 468 may abut the axle 460 so that the roller unit isnormally kept at a second opposite end of the slot 464. Although oneconstruction of the roller unit is shown, it should be appreciated thatmany alternate constructions will be apparent to those of skill in theart for providing a rolling interface between the shuttle 436 and thelockbolt 420.

The roller unit is operatively coupled with the lockbolt 420 through alockbolt carrier 421. The lockbolt carrier 421 includes a central recess461 that receives a portion of the link 456. The axle 460 of the rollerunit extends through a pair of matching cam slots 448 in the lockboltcarrier 421 and through the slot 464 in the link 456, thereby couplingthe link 456 with the lockbolt carrier 421. The lockbolt 420 is coupledwith the lockbolt carrier 421 by engagement between a protrusion 420A ofthe lockbolt 420 and an aperture 421A in the lockbolt carrier 421 thatenables the lockbolt 420 and the lockbolt carrier 421 to move togetherunitarily along the lockbolt axis B4. Although provided as separatecomponents in the illustrated construction, the lockbolt 420 and thelockbolt carrier 421 constitute a lockbolt unit and may be replaced insome constructions of the steering lock 400 by a lockbolt unit ofalternate construction, such as a one-piece lockbolt that is directlycoupled to the shuttle 436.

Both the roller bearings 476 of the roller unit and the lockbolt carrier421 are guided for linear movement by internal features of the housing408. Portions of the lockbolt carrier 421 contact a pair of guidesurfaces 484 (FIG. 14) on the inside of the first housing portion 408Aso that the lockbolt carrier 421 is moved parallel to the lockbolt axisB4 when actuated by the shuttle 436. Furthermore, guide surfaces 478A,478B on both the first and second housing portions 408A, 408B constrainthe movement of the roller unit to a plane P4 that is substantiallyperpendicular to the lockbolt axis B4. Thus, the roller unit movesperpendicular to the lockbolt axis B4 although the link 456 has thefreedom to assume various angular orientations during movement of thecrank 443. Because the axle 460 is supported at both its ends by theroller bearings 476, the axle 460 experiences low friction rolling alongthe surfaces of the cam slots 448 in the lockbolt carrier 421 ratherthan sliding. Likewise, the outer portions of the roller bearings 476experience low friction rolling along either pair of the guide surfaces478A, 478B rather than sliding.

The operation and various states of the steering lock 400 are describedwith primary reference to FIGS. 15-17. In FIG. 15, the steering lock 400is in a locked state, which is to say that the lockbolt 420 is extendedalong the axis B4 to its locked position so that it is received in oneof the grooves 424 of the steering member 404 and rotation of thesteering member 404 is inhibited. The roller unit of the shuttle 436 ispositioned on surfaces 448B of the cam slots 448 that extendsubstantially perpendicular to the lockbolt axis B4 to serve as blockingsurfaces so that the shuttle 436 blocks or physically obstructs themovement of the lockbolt 420 from the locked position toward theunlocked position of FIG. 16. In the illustrated construction, theblocking surfaces 448B, while extending substantially perpendicular tothe lockbolt axis B4, are positioned along the lockbolt axis B4 tointersect with the lockbolt axis B4. Any force applied from the steeringmember 404 to the lockbolt 420 in the unlocking direction is reactedagainst simply by contact between the roller bearings 476 and the guidesurfaces 478B of the second housing portion 408B, which aresubstantially perpendicular to the lockbolt axis B4. Such a force fromthe steering member 404 is unable to backdrive the shuttle 436 or theactuator 432, so that the lockbolt 420 passively but reliably stays inthe locked position. No bias force along the lockbolt axis B4 is appliedto the lockbolt 420 in the locked position, and no energy or resistancefrom the actuator 432 is used to keep the lockbolt 420 in the lockedposition.

To unlock the steering lock 400 and release the steering member 404, theshuttle 436 is moved from the blocking position to the non-blockingposition. The actuator 432 is energized to rotate the output shaft 440,which rotates the crank 443 (counter-clockwise as viewed in FIGS. 15-17)to move the link 456. The link 456 is moved so as to pull the rollerunit, and particularly the axle 460, off of the blocking surfaces 448Band into portions of the cam slots 448 that are inclined with respect tothe lockbolt axis B4 to provide inclined cam surfaces 448A. In theillustrated construction, the cam surfaces 448A of each cam slot 448 areoriented at approximately 45 degrees with respect to the lockbolt axisB4. When the roller unit is pulled by the link 456 away from theblocking surfaces 448B (to the right in FIGS. 15-17), the contactbetween the axle 460 and the inclined cam surfaces 448A urges thelockbolt carrier 421 and the lockbolt 420 toward the unlocked positionof FIG. 16. Although the power of the actuator 432 is applied in amanner to move the lockbolt 420 from the locked position to the unlockedposition, the lockbolt 420 is substantially self-releasing due to theconfiguration of the tapered tip 452, which is similar to the tip 152described above. Thus, even if a strong force is applied to the lockbolt420 by the steering member 404, this force tends to automaticallyrelease the lockbolt 420 from the steering member 404 rather thanwedging the lockbolt 420 and holding it in the locked position againstthe power of the actuator 432. Therefore, the actuator 432 does not needa high power rating to cope with the extraction of a wedged lockboltcondition.

Movement into the unlocked position is completed when the roller unitreaches a position in the cam slots 448 that is opposite the blockingsurfaces 448B as shown in FIG. 16. This position defines thenon-blocking position of the shuttle 436. In the illustratedconstruction, the crank 443 positions the shuttle 436 as remotely aspossible from the lockbolt axis B4 in the non-blocking position. Thecoil spring 468 or other lost motion device holds no residual orpotential energy in the unlocked position, and the lockbolt 420 is notsubject to any other bias force in the unlocked position such that theactuator 432 can simply be turned off and the lockbolt 420 sitspassively in the unlocked position until actuated to lock again. Theactuator 432 is automatically stopped upon achieving the unlockedposition of FIG. 16. In one construction, a magnetic switch on themounting plate/PCB 411 may sense the orientation of the crank 443 bysensing a magnet or magnetic portion of the crank 443 to signal theactuator 432 to turn off. Excessive travel of the crank 443 is alsoblocked by interference between a protrusion 447 on the driving portion443B of the crank 443 and an abutment 449 on the inside of the firsthousing portion 408A.

In order to lock the steering lock 400 and restrict movement of thesteering member 404, the actuator 432 is energized to rotate the outputshaft 440, which rotates the crank 443 (clockwise as viewed in FIGS.15-17) to move the link 456. The link 456 is moved so as to push theroller unit, and particularly to push the axle 460 via the coil spring468 or other lost motion device, along the inclined cam surfaces 448Atoward the blocking surfaces 448B. Because the roller unit isconstrained to move within the plane P4, the movement of the roller unittoward the blocking surfaces 448B (to the left as viewed in FIGS.15-17), causes the lockbolt carrier 421 and the lockbolt 420 to movealong the axis B4 toward the steering member 404. The actuator 432 isautomatically stopped upon actuating the crank 443 an amountcorresponding to that required for actuating the lockbolt 420 to thelocked position via the shuttle 436. Various types of open-loop orclosed-loop controls may be used to control on/off operation of theactuator 432. In some constructions, a magnetic switch on the mountingplate/PCB 411 may sense the orientation of the crank 443 by sensing amagnet or magnetic portion of the crank 443 to signal the actuator 432to turn off. As shown in FIG. 15, the crank 443 may be rotated just pasta top dead center position (in which the link 456 and the coil spring468 intersect with the crank axis D4) so that any residual or potentialenergy stored in the spring 468 in the locked position urges the crank443 to rotate further clockwise. Excessive travel of the crank 443 inthis direction is blocked by interference between the protrusion 447 onthe driving portion 443B of the crank 443 and the abutment 449 on theinside of the first housing portion 408A. Thus, the locked position isstable without continued energisation of the actuator 432, and althougha slight bias force may exist within the shuttle 436 (e.g., in thespring 468 or other lost motion device between the link 456 and theroller unit), the lockbolt 420 and the lockbolt carrier 421 are notbiased in either direction along the lockbolt axis B4 when in the lockedposition. Although illustrated in FIG. 15 as rotating slightly past topdead center, the crank 443 may stop substantially at top dead center toprovide a stable locked position that is resistant to backdriving by thelink 456.

The above description of locking the steering member 404 by moving thelockbolt 420 to the locked position assumes that the lockbolt 420 isaligned with a groove 424 of the steering member 404 when actuated. Assuch, the lost motion device transfers the actuating energy from theactuator to the roller unit and to the lockbolt 420, substantiallywithout absorbing such energy. However, it may not always be the casethat the lockbolt 420 is aligned with a groove 424 of the steeringmember 404 when actuated. Similar to the steering locks 100, 200, 300described above, the shuttle 436 of the steering lock 400 of FIGS. 13-17is configured to store energy supplied by the actuator 432 when theshuttle 436 is actuated to move the lockbolt 420 and the lockbolt 420abuts a rib 428 of the steering member 404. When these circumstancesarise in the illustrated construction, the actuator 432 moves the guidebody or link portion 456 of the shuttle 436 to the positioncorresponding to the lockbolt-blocking position, but the roller unitdoes not achieve the blocking position. Instead, the coil spring 468 iscompressed between the axle 460 of the roller unit and the end 464A ofthe slot 464 as shown in FIG. 17. The energy supplied by the actuator432 is stored by the coil spring 468, and the actuator 432 is turnedoff. Although shown in the top dead center position in FIG. 17, the link456 may be rotated slightly past top dead center (further clockwise asviewed in FIGS. 15-17) as described above with respect to the normallocking position. Because the crank 443 and the link 456 are stable inthis position and do not need to be actively maintained by the actuator432, the steering lock 400 can remain in this imminent-lock positionwithout any significant power draw (i.e., no power to the actuator 432,and only nominal power to the associated circuit which may be used tomaintain active sensors or the like) and without reaching a faultcondition. From the state shown in FIG. 17, the lockbolt 420 will moveto the locked position by the energy stored in the lost motion device assoon as the steering member 404 is moved to align a groove 424 with thelockbolt 420.

FIGS. 18-22 illustrate a steering lock 500 according to yet anotherconstruction. The steering lock 500 of FIGS. 18-22 is similar in someaspects to the steering locks 100, 200, 300, 400 of FIGS. 1-17.Reference characters, with leading digits incremented by 100, arere-used where appropriate for consistency. Reference is made to theabove description of the steering locks 100, 200, 300, 400 for featuresand aspects of the steering lock 500 of FIGS. 18-22 not specificallydescribed below.

As shown in FIGS. 18 and 19, a housing 508 encloses an actuation device516 for actuating a lockbolt 520. Although only a portion of the housing508 is shown, it should be understood that the housing 508 can includefirst and second portions similar to housings shown in other figures anddescribed above. Similar to the steering locks described above, thehousing 508 is configured to be mounted at a predetermined locationproximate a steering member (not shown), and the actuation device 516 ofthe steering lock 500 is configured to selectively move the lockbolt 520out of the housing 508 from a steering member-unlocking position orsimply “unlocked” position (FIG. 20) to a steering member-lockingposition or simply “locked” position (FIGS. 18, 19, and 21). In theillustrated construction, the lockbolt 520 is movable between the lockedand unlocked positions along an axis B5 that is substantiallyperpendicular to an axis of the steering member.

Turning now to the mechanical construction of the actuation device 516,certain aspects are generally similar to aspects already described withrespect to at least one of the steering locks 100, 200, 300, 400described above. For example, the actuation device 516 utilizes ashuttle 536 to deploy the lockbolt 520 to the locked position. Theshuttle 536 is movable between a blocking position that obstructsmovement of the lockbolt 520 to the steering member-unlocking positionand a non-blocking position that does not obstruct movement of thelockbolt 520 to the steering member-unlocking position. Furthermore, alost motion device is provided to store the actuation energy when thelockbolt 520 is actuated to move from the unlocked position to thelocked position, but is blocked (e.g., when aligned with a rib of thesteering member rather than a groove) from immediately achieving thelocked position. Similar to the steering lock 400, the steering lock 500is completely passive, as no bias member is provided to urge thelockbolt 520 along the lockbolt axis B5 to one position or the other.The specific construction and operation of the actuation device 516 areexplained in detail below.

The actuator 532, which may be an electric motor, is coupled to theoutput shaft 540 to rotate the output shaft 540 about the axis C5. Inthe illustrated construction, the output shaft 540 is constructed as aworm gear that drives a crank or rotary drive member 543, e.g., via ameshing engagement with a gear portion 543A at the outer periphery ofthe rotary drive member 543, such that the rotary drive member 543 isdrivable by the actuator 532. The rotary drive member 543 also includesa driving portion 543B radially inward of the gear portion 543A. Therotary drive member 543 is configured to rotate about an axis D5 whenthe output shaft 540 is rotated by the actuator 532. Unlike the crank443 of the steering lock 400, the axis D5 is substantially parallel tothe lockbolt axis B5 such that the rotary drive member 543 rotates in aplane P5 that is substantially perpendicular to the lockbolt axis B5.However, the rotary drive member 543 can have another orientationrelative to the lockbolt axis B5, for example, similar to the crank 443and lockbolt 420 if desired. A pin or axle 544 rotatably supports therotary drive member 543 relative to the housing 508. As describedfurther below, the driving portion 543B of the rotary drive member 543is a cam.

The shuttle 536 is coupled to the rotary drive member 543 and configuredto apply an actuating force to the lockbolt 520. The shuttle 536includes a guide body or link 556 coupled to the rotary drive member 543via a follower 557 and a lockbolt actuator coupled to the link 556through a lost motion device. Although not illustrated in detail, thelockbolt actuator can be a roller unit similar to that described abovewith respect to the steering lock 400. The lockbolt actuator can includea pin or axle 560, and the lost motion device includes a biasing membersuch as a coil spring 568 positioned in an opening or slot 564 of thelink 556. As seen in the drawings, a first end of the coil spring 568may abut a first end 564A of the slot 564, and the opposing end of thecoil spring 568 may abut the axle 560 so that the pin 560 is normallykept at a second opposite end of the slot 564. Although illustratedschematically in FIGS. 20 and 21, it should be appreciated that thespring 568 may be constructed and retained similar to that of thesteering lock 400.

A portion of the link 556 having the slot 564 is substantially co-planarwith the rotary drive member 543, and the axle 560 is constrained by thehousing 508 to travel linearly within a plane, which is parallel to orthe same as the plane P5 in which the rotary drive member 543 rotates.The link 556 is provided with an offset portion 556A carrying thefollower 557 as shown in FIGS. 20 and 21 to engage the cam drivingportion 543B of the rotary drive member 543. The cam driving portion543B of the rotary drive member 543 is provided as a spiral cam (e.g.,spiral cam groove 587 bounded by inner and outer walls 589A, 589B asshown in FIG. 22). The spiral cam groove 587 can include severaldistinct segments as shown. A first segment 587A is provided as aradially outermost portion and is a substantially uniform radius dwellsegment, the passage of which causes substantially no actuation of thefollower 557 and thus, no movement of the shuttle 536. Extending fromthe first segment 587A in the counter-clockwise direction in FIG. 22 isa second segment 587B, which is a spiral segment of substantiallyuniformly-decreasing radius. The second segment 587B forms a majority ofthe groove 587, the passage of which causes substantially fixed-speedtranslation of the follower 557 and the shuttle 536. Extending from thesecond segment 587B in the counter-clockwise direction in FIG. 22 is athird segment 587C. The third segment 587C extends further radiallyinward over a short angular length to provide a more drastic movement ofthe follower 557 and the shuttle 536 (e.g., faster movement, assumingequivalent angular velocity of the rotary drive member 543). Thefurthest radially inward segment 587D is a fourth segment provided as adwell segment with substantially uniform radius.

The shuttle 536 is operatively coupled with the lockbolt 520 through alockbolt carrier 521 similar to the above description of the steeringlock 400. The lockbolt 520 and the lockbolt carrier 521 are secured tomove unitarily together. Although provided as separate components in theillustrated construction, the lockbolt 520 and the lockbolt carrier 521constitute a lockbolt unit and may be replaced in some constructions ofthe steering lock 500 by a lockbolt unit of alternate construction, suchas a one-piece lockbolt that is directly coupled to the shuttle 536. Theaxle 560 in the slot 564 in the link 556 extends through a cam slot(s)548 in the lockbolt carrier 521, thereby coupling the link 556 with thelockbolt carrier 521.

Unlike the link 456 of the steering lock 400 which has the freedom toassume various angular orientations during movement of the actuatingcrank 443, the link 556 (and thus, the shuttle 536 as a whole) is guidedfor linear movement relative to the housing 508. The lockbolt carrier521 is also guided for linear movement by internal features of thehousing 508 such that the lockbolt carrier 521 is moved parallel to thelockbolt axis B5 when actuated by the shuttle 536.

The operation and various states of the steering lock 500 are describedwith primary reference to FIGS. 19-21. In FIGS. 19 and 21, the steeringlock 500 is in a locked state, which is to say that the lockbolt 520 isextended along the axis B5 to its locked position so that it is receivedin one of the grooves of the steering member and rotation of thesteering member is inhibited. The axle 560 of the shuttle 536 ispositioned on surface(s) 548B of the cam slot(s) 548 that extendsubstantially perpendicular to the lockbolt axis B5 to serve as blockingsurfaces so that the shuttle 536 blocks or physically obstructs themovement of the lockbolt 520 from the locked position toward theunlocked position of FIG. 20. In the illustrated construction, theblocking surfaces 548B are offset from the lockbolt axis B5 in thedirection of the shuttle 536 and the rotary drive member 543. Any forceapplied from the steering member to the lockbolt 520 in the unlockingdirection is reacted against simply by the axle 560 and correspondingsupports within the housing 508, which are substantially perpendicularto the lockbolt axis B5. The reaction may also be borne by one or moreroller bearings provided on the axle 560 to guide the axle 560 along thehousing supports. Such a force from the steering member is unable tobackdrive the shuttle 536 or the actuator 532, so that the lockbolt 520passively but reliably stays in the locked position. No bias force alongthe lockbolt axis B5 is applied to the lockbolt 520 in the lockedposition, and no energy or resistance from the actuator 532 is used tokeep the lockbolt 520 in the locked position. The follower 557 ispositioned within the first segment 587A of the spiral cam groove 587when the steering lock 500 is in the locked state.

To unlock the steering lock 500 and release the steering member, theshuttle 536 is moved from the blocking position to the non-blockingposition. In order to move the shuttle 536, the actuator 532 isenergized to rotate the output shaft 540, which rotates the rotary drivemember 543 clockwise as shown in FIG. 22 so that the follower 557 entersthe second segment 587B of the spiral cam groove 587. As the rotarydrive member 543 rotates through the angle of the second segment 587B,the follower 557 and the link 556 are driven linearly at a substantiallyfixed ratio with the angular rotation of the drive member 543. The link556 is moved so as to pull the axle 560 off of the blocking surface(s)548B and into portions of the cam slots 548 that are inclined withrespect to the lockbolt axis B5 to provide inclined cam surfaces 548A(FIG. 19). In the illustrated construction, the cam surface(s) 548A isoriented at approximately 45 degrees with respect to the lockbolt axisB5. When the axle 560 is pulled by the link 556 away from the blockingsurface(s) 548B, the contact between the axle 560 and the inclined camsurface 548A urges the lockbolt carrier 521 and the lockbolt 520 towardthe unlocked position. Although the power of the actuator 532 is appliedin a manner to move the lockbolt 520 from the locked position to theunlocked position, the lockbolt 520 is substantially self-releasing dueto the configuration of the tapered tip 552 (not visible indrawings—tapered in the direction into and out of the page as shown),which is similar to the tip 152 described above. Thus, even if a strongforce is applied to the lockbolt 520 by the steering member, this forcetends to automatically release the lockbolt 520 from the steering memberrather than wedging the lockbolt 520 and holding it in the lockedposition against the power of the actuator 532. Therefore, the actuator532 does not need a high power rating to cope with the extraction of awedged lockbolt condition.

Once the lockbolt 520 is mostly or fully removed from engagement withthe steering member, the follower 557 passes through the third segment587C of the spiral cam groove 587, by which the follower 557 is moved atan accelerated ratio with respect to the angular rotation of the rotarydrive member 543. This enables the lockbolt 520 to more quickly reachthe unlocked position, when the actuator 532 is substantially unloaded.

Movement into the unlocked position is completed when the follower 557passes into the fourth segment 587D of the spiral cam groove 587, whichcorresponds to the axle 560 reaching a position in the cam slot(s) 548that is opposite the blocking surface 548B as shown in FIG. 20. Thisposition defines the non-blocking position of the shuttle 536. In theillustrated construction, the rotary drive member 543 positions theshuttle 536 as remotely as possible from the lockbolt axis B5 in thenon-blocking position. The coil spring 568 or other lost motion deviceholds no residual or potential energy in the unlocked position, and thelockbolt 520 is not subject to any other bias force in the unlockedposition such that the actuator 532 can simply be turned off and thelockbolt 520 sits passively in the unlocked position until actuated tolock again. The actuator 532 is automatically stopped upon achieving theunlocked position of FIG. 20. In one construction, a magnetic switch maysense the orientation of the rotary drive member 543 by sensing a magnet543M or magnetic portion of the rotary drive member 543 (FIG. 18) tosignal the actuator 532 to turn off.

In order to lock the steering lock 500 and restrict movement of thesteering member, the actuator 532 is energized to rotate the outputshaft 540, which rotates the rotary drive member 543 to move the link556. The link 556 is moved so as to push the axle 560 via the coilspring 568 or other lost motion device, along the inclined cam surfaces548A toward the blocking surface 548B. Because the axle 560 isconstrained to move within the plane P5, the movement of the axle 560toward the blocking surface 548B (to the left as viewed in FIGS. 19-21),causes the lockbolt carrier 521 and the lockbolt 520 to move along theaxis B5 toward the steering member. The actuator 532 is automaticallystopped upon actuating the rotary drive member 543 an amountcorresponding to that required for actuating the lockbolt 520 to thelocked position via the shuttle 536. Various types of open-loop orclosed-loop controls may be used to control on/off operation of theactuator 532. In some constructions, a magnetic switch may sense theorientation of the rotary drive member 543 by sensing the magnet 543M ormagnetic portion of the rotary drive member 543 to signal the actuator532 to turn off.

As the actuator 532 is operated to rotate the rotary drive member 543and lock the steering lock 500, the follower 557 is driven through thespiral cam groove 587 from the fourth segment 587D toward the firstsegment 587A. This produces a sequence including a short dwell, a quickinitial movement, a more gradual movement over a majority of therotation, and a final dwell. Due to the constant radius of the firstsegment 587A of the spiral cam groove 587, as well as the engagementbetween the gear portion 543A and the worm gear 540, the locked positionis stable without continued energisation of the actuator 532. Although aslight bias force may exist within the shuttle 536 (e.g., in the spring568 or other lost motion device between the link 556 and the axle 560),the lockbolt 520 and the lockbolt carrier 521 are not biased in eitherdirection along the lockbolt axis B5 when in the locked position.

The above description of locking the steering member by moving thelockbolt 520 to the locked position assumes that the lockbolt 520 isaligned with a groove of the steering member when actuated. As such, thelost motion device transfers the actuating energy from the actuator tothe axle 560 and to the lockbolt 520, substantially without absorbingsuch energy. However, it may not always be the case that the lockbolt520 is aligned with a groove of the steering member when actuated, andin these instances, the shuttle 536 operates similar to those describedabove to store energy supplied by the actuator 532 when the shuttle 536is actuated to move the lockbolt 520 and the lockbolt 520 abuts a rib ofthe steering member. The rotary drive member 543 is rotated to aposition corresponding to the locked position, but the axle 560, thelockbolt carrier 521, and the lockbolt 520 are not moved. The energysupplied by the actuator 532 is instead stored by the coil spring 568.Because the rotary drive member 543 and the link 556 are stable in thisposition and do not need to be actively maintained by the actuator 532,the steering lock 500 can remain in this imminent-lock position withoutany significant power draw (i.e., no power supplied to the actuator 532,and only nominal power to the associated circuit which may be used tomaintain active sensors or the like) and without reaching a faultcondition. From this state, the lockbolt 520 will move to the lockedposition by the energy stored in the lost motion device as soon as thesteering member is moved to align a groove with the lockbolt 520.

FIGS. 23 and 24 illustrate a steering lock 600 and actuation device 616according to yet another construction. The steering lock 600 of FIG. 23,including the actuation device 616 of FIG. 24, is similar in someaspects to the steering locks 100, 200, 300, 400, 500 of FIGS. 1-22.Reference characters, with leading digits incremented by 100, arere-used where appropriate for consistency. Reference is made to theabove description of the steering locks 100, 200, 300, 400, 500 forfeatures and aspects of the steering lock 600 and actuation device 616of FIGS. 23 and 24 not specifically described below.

The steering lock 600 of FIG. 23 features an actuation device 616 asbest shown in FIG. 24 that includes a rotary drive member 643 that issimilar to the rotary drive member 543 shown in FIG. 22, and includes anouter gear portion 643A and a radially inward driving portion 643Bprovided as a spiral cam (e.g., spiral cam groove 687 bounded by innerand outer walls 689A, 689B). The spiral cam groove 687 includes severaldifferently shaped portions 687A-D, which can be similar to those of thecam groove 587 and can function in a similar manner. Although the rotarydrive member 643 generally actuates the lockbolt 620 through a shuttle636 with a lost motion device (e.g., spring 668), and with the shuttle636 being restrained (e.g., by corresponding guide features in thehousing 608) to move back and forth along a linear path similar to theshuttle 536 of FIGS. 18-21, the shuttle 636 has a different constructionthan the shuttle 536.

Rather than the one-piece guide body or link 556, the guide body or linkis formed from two separate link members 656A, 656B slidably coupledtogether. The sliding interface can be defined as a male-femaleinterface. In the illustrated construction, the first link member 656A(closest to the rotary drive member 643) forms a female component, andthe second link member 656B forms a male component. The first linkmember 656A includes a slot or opening 664, and a portion of the secondlink member 656B is positioned within the opening 664 in the first linkmember 656A. The spring 668 or other lost motion device is positionedsubstantially within the opening 664 between the two link members 656A,656B to bias them to an extended-apart configuration as shown in FIG.24. In the extended-apart configuration, the spring 668 bears against afirst end 664A of the opening 664 and biases the second link member 656Binto abutting contact with an opposite end of the opening 664. Either orboth of the link members 656A, 656B can include a spring retainerfeature to maintain the spring 668 in a desired position or orientation.The axle 660 or other member movable into and out of blockingrelationship with the lockbolt 620 is fixed to the second link member656B to move directly therewith.

Another difference between the steering lock 600 and the steering lock500 of FIGS. 18-22 is the orientation of the actuator 632. As shown inthe drawings, the axis C6 of the worm gear output shaft 640 issubstantially parallel with the linear path of the shuttle 636, whereasthe axis C5 is substantially skewed with respect to the linear path ofthe shuttle 536. Both constructions represent viable solutions, and theoptimum orientation of these and other components generally depends uponseveral factors that can include the desired gear ratio, the size of theactuator, and the size and shape of the available packaging space forthe steering lock within a particular vehicle.

FIGS. 25-33 illustrate a steering lock 700 and actuation device 716according to yet another construction. The steering lock 700, includingthe actuation device 716 of FIGS. 27-33, is similar in some aspects tothe steering locks 100, 200, 300, 400, 500, 600 of FIGS. 1-24. Referencecharacters, with leading digits incremented by 100, are re-used whereappropriate for consistency. Reference is made to the above descriptionof the steering locks 100, 200, 300, 400, 500, 600 for features andaspects of the steering lock 700 and actuation device 716 of FIGS. 25-33not specifically described below.

The steering lock 700 of FIG. 25 includes a housing 708 and a cover 712which cooperates with the housing 708 to enclose an actuation device 716for controlling the state of the lockbolt 720 for selectively locking asteering ring (not shown). The housing 708 includes mounting portions710 at each of two opposing ends of the housing 708, one of which isadjacent the lockbolt 720 and the other of which is remote from thelockbolt 720. The two mounting portions 710 are provided as generallycylindrical or tubular formations that are parallel to one another, andeach extend across substantially the entire width of the housing 708.The axes of both of the mounting portions 710 are substantiallyperpendicular to the lockbolt axis B7. One of the mounting portions 710(left in FIGS. 26-29) may be slightly elongated in a directionperpendicular to its axis (and perpendicular to the lockbolt axis B7) toallow for tolerancing when mounting the steering lock 700 to adjacentstructure within a vehicle.

The actuation device 716 includes an actuator 732, which can be similarin many aspects to the actuators described above. For example, theactuator 732 can be an electric motor having an output shaft 740defining an axis C7. However, the actuator 732 of the steering lock 700has a generally rectangular body shape having four generally flat sides.This can provide alternate mounting configurations and potentiallyquieter operation. A shuttle 736 having a similar function to theshuttles described above is drivable by the actuator 732 betweenblocking and non-blocking positions. In view of the above description, adetailed description of the operation of the actuation device 716 is notrequired for understanding, but it should be noted that the shuttle 736drives the lockbolt 720 to the locked state by moving from thenon-blocking position (retracted) to the blocking position (extended),and blocks the lockbolt 720 from moving to the unlocked state when inthe blocking position. Thus, the steering lock 700 can passively butpositively retain the lockbolt 720 in the locked state, and the lockbolt720 can be unbiased along the axis B7. The shuttle 736 also storesenergy upon actuation to the blocking position when the lockbolt 720 isaligned with a rib or projection of the steering ring. The shuttle 736is driven by a parallel gear set including a first gear 741 on theoutput shaft 740 and a second gear 743, which is larger in diameter thanthe first gear 741. The first and second gears 740, 741 can besubstantially enclosed by a sub-housing 746. The sub-housing 746 caninclude multiple pieces that fit together (e.g., snap-fit together) andgenerally conform to the shape of the first and second gears 741, 743.The sub-housing 746 can provide an additional sound containmentstructure within the housing 708 so that noise from operation of thegears 741, 743 as measured outside the housing 708 (e.g., within avehicle cabin) is further reduced or eliminated.

The second gear 743 includes threads engaged with threads 756T of theguide body 756, so that the guide body 756 is moved axially when thesecond gear 743 is rotated in place. In the illustrated construction,the interior of the second gear 743 is provided with female threads andthe threads 756T on the guide body 756 are external male threads, butother arrangements may be provided. Lost motion and energy storage areprovided by the shuttle 736 when the shuttle 736 is actuated to theblocking position and the lockbolt 720 is aligned with a rib of thesteering ring rather than a groove. The lost motion device includes aspring 768 positioned on a post portion 759 of the guide body 756,between a transverse flange portion 756F and a shaft 760. The shaft 760is positioned within one or more cam slots 748 of the lockbolt carrier721, and also within a slot 764 of the guide body 756. The outerportions of the shaft 760 are guided by slots 778 or other surfaces ofthe housing 708. The transverse flange 756F of the guide body 756 isalso guided for linear movement within the housing 708. A resilientbumper 758 (FIGS. 32 and 33) may be provided within the housing 708 andconfigured to provide soft stops or limits to the motion of the guidebody 756. As illustrated, the bumper 758 is a U-shaped member with twoupstanding stops, one at either end. In other constructions, the bumper758 can have other shapes, or individual bumpers are provided for thefore and aft stops.

A sensor magnet 756M is coupled to the guide body 756, and may becoupled to the transverse flange 756F. The magnet 756M can be held in apolymer body and snapped, clipped, threaded, bonded, or otherwiseattached to the transverse flange 756F. In the illustrated construction,the magnet 756M is positioned on a lateral side of the transverse flange756F to move along a magnetic switch formed by two magnetic sensors 781on the PCB 711 positioned adjacent the actuation device 716. Themagnetic sensors 781 can be configured to sense the two limit positionsof the guide body 756 and provide feedback to a controller whichcontrols operation of the actuator 732. An additional sensor may beprovided to directly sense the position of the lockbolt 720. Forexample, another magnet 720M (FIGS. 30 and 31) may be coupled to thelockbolt 720 or the lockbolt carrier 721 for detection by a magneticsensor (not shown) coupled to the PCB 711 adjacent the lockbolt 720.

FIG. 34 illustrates a steering lock 800 similar to the steering lock 700of FIGS. 25-33, and in fact features the same actuation device 716.However, the steering lock 800 of FIG. 34 includes a housing 808 havingan alternate mounting interface than that of the housing 708. Instead ofthe cylindrical mounting portions 710 that extend substantiallyperpendicular to the lockbolt axis B7, the housing 808 includes aplurality of individual mounting portions 810 at each end, each providedas flanges with apertures that are substantially parallel with thelockbolt axis B7. The position and number of mounting portions 810 mayvary with different applications for different vehicle packagingconstraints. Although not shown, the steering lock 800 includes a coversimilar to the cover 712 shown in FIGS. 25 and 26. Additional featuresand operation of the steering lock 800 are not described in detailherein as they will be understood from the preceding description.

What is claimed is:
 1. A steering lock for selectively inhibitingrotation of a rotary steering member having a rib, the steering lockcomprising: a lockbolt movable along a first axis between a steeringmember-locking position, in which a distal tip of the lockbolt ispositioned in interference with the rib, and a steering member-unlockingposition, in which the distal tip of the lockbolt is positioned out ofinterference with the rib; a shuttle movable between a non-blockingposition, in which the shuttle does not obstruct movement of thelockbolt from the steering member-locking position to the steeringmember-unlocking position, and a blocking position, in which the shuttleobstructs movement of the lockbolt out of the steering member-lockingposition; an actuator operatively coupled to the shuttle and operable todrive the lockbolt to the steering member-locking position by moving theshuttle from the non-blocking position to the blocking position; anoutput gear drivable by the actuator; and a rotary drive member having afirst portion formed with gear teeth meshed with the output gear, andfurther having a second portion formed with a driving structure engagedwith a follower structure of the shuttle whereby the shuttle isconfigured to translate axially toward and away from the first axis whenthe rotary drive member is rotated in place.
 2. The steering lock ofclaim 1, wherein the driving structure of the rotary drive memberincludes a spiral cam.
 3. The steering lock of claim 2, wherein thespiral cam includes a spiral cam groove, and the follower structure ofthe shuttle is positioned within the spiral cam groove.
 4. The steeringlock of claim 2, wherein the spiral cam includes first and secondconstant radius dwell portions at radially inner and outer ends, andbetween the first and second dwell portions, further includes a majorityportion having a radius decreasing substantially uniformly from thefirst dwell portion, and a minority portion having a more drastic radialdecrease than the majority portion in a direction toward the seconddwell portion.
 5. The steering lock of claim 2, wherein the rotary drivemember rotates about a second axis parallel to the first axis.
 6. Thesteering lock of claim 2, further comprising a magnetic element coupledto the rotary drive member and at least one magnetic sensor positionedat a fixed location adjacent the rotary drive member.
 7. The steeringlock of claim 1, wherein the driving structure of the rotary drivemember includes a threaded drive portion and the shuttle includes athreaded follower structure drivably coupled to the threaded driveportion of the rotary drive member.
 8. The steering lock of claim 7,wherein the threaded drive portion of the rotary drive member is formedof an aperture with female threads and the threaded follower structureof the shuttle includes male threads.
 9. The steering lock of claim 7,wherein the rotary drive member has an outer profile including gearteeth meshed with an output gear of the actuator, the steering lockfurther comprising a gear set sub-housing substantially enclosing thegear teeth of the rotary drive member and the output gear.
 10. Thesteering lock of claim 7, wherein the shuttle includes a unitary guidebody including the follower at a first end, a post portion with a slotat a second end for slidably receiving a lockbolt actuator, and atransverse flange between the first and second ends, the transverseflange having a first portion engaging a resilient bumper for definingfirst and second stops of the shuttle and a second portion receiving amagnetic element for position detection of the shuttle by at least onemagnetic sensor positioned at a fixed location adjacent the shuttle. 11.The steering lock of claim 10, wherein two magnetic sensors are providedon a printed circuit board fixedly positioned within a housing of thesteering lock that substantially encloses the actuator and the shuttleand partially encloses the lockbolt.
 12. The steering lock of claim 1,wherein the shuttle is constrained to translate axially along a paththat is substantially perpendicular to and intersecting with the firstaxis.
 13. The steering lock of claim 1, further comprising a lost motionconnection between the actuator and the lockbolt, wherein motive forcefrom the actuator is transmitted through the lost motion connection todrive the lockbolt to the steering member-locking position when the ribis not aligned with the first axis, and wherein motive force from theactuator is taken up by the lost motion connection when the rib isaligned with the first axis.
 14. The steering lock of claim 13, whereinthe lost motion device includes a spring positioned between the followerof the shuttle and a lockbolt actuator portion of the shuttle.
 15. Thesteering lock of claim 14, wherein the lockbolt actuator portion of theshuttle is constrained to move along a linear path that is perpendicularto the first axis.
 16. The steering lock of claim 15, further comprisinga housing enclosing the shuttle and the actuator and partially enclosingthe lockbolt, wherein the lockbolt actuator portion of the shuttle isconstrained to move along the linear path by at least one guide surfaceof the housing.
 17. The steering lock of claim 14, wherein the lockboltactuator portion includes a shaft extending through a slot formed in apost portion of the shuttle, the shaft being biased to one end of theslot by the spring, and wherein the spring is a coil spring encirclingthe post portion.
 18. The steering lock of claim 14, wherein the shuttleincludes first and second link members slidably coupled together,whereby one of the first and second link members is received in anopening of the other, and wherein the spring is positioned within theopening.
 19. The steering lock of claim 1, further comprising a housingenclosing the shuttle and the actuator and partially enclosing thelockbolt, wherein the follower of the shuttle is constrained to movealong a linear path by at least one guide surface of the housing. 20.The steering lock of claim 1, wherein a first inclined cam surface isprovided between the shuttle and the lockbolt so that substantiallylinear movement of the shuttle to the blocking position in a directionsubstantially perpendicular to the first axis is configured to move thelockbolt to the steering member-locking position.
 21. The steering lockof claim 20, wherein a second inclined cam surface is provided betweenthe shuttle and the lockbolt so that substantially linear movement ofthe shuttle to the non-blocking position in a direction substantiallyperpendicular to the first axis is configured to move the lockbolt tothe steering member-unlocking position.
 22. The steering lock of claim1, wherein the actuator is an electric motor.
 23. The steering lock ofclaim 1, wherein the lockbolt is unbiased along the first axis.
 24. Thesteering lock of claim 1, wherein the lockbolt is part of an integrallymovable lockbolt unit that further includes a separately-formed lockboltcarrier.
 25. The steering lock of claim 24, wherein the shuttle shares acam interface with the lockbolt carrier for moving the lockbolt to atleast one of the steering member-locking position and the steeringmember-unlocking position.
 26. The steering lock of claim 1, wherein thesecond portion formed with the driving structure is positioned entirelywithin the first portion formed with the gear teeth.